Single 485...not quite a drop in. Dan@FI did the mod as we decided to step up from a 340 for ***** and gigs. All I can really say is that we have in inline filter replacing the in-tank.
AFAIK, it is in the stock assembly, just do not know how much it was altered to fit. Surprisingly the 485 is not loud at all, lol. After hearing a 400 and many 340s whine and hum, the big 485 has been silent thus far.
No UOA, my first oil change was at maybe 2000 miles. I ran most of the oil and filter load through a paper filter, no metal, no sheen, so that's a great sign. Next oil change in about a month will be going to blackstone for sure. I wanted to do the home test as a knee-jerk reaction to a friends boosted 350 having crazy amounts of metal when ran through a paper towel.